Is it permissible and advisable to drain two bathroom lavs and a washing machine through a single 2 inch drain pipe with a run of less that 4 feet to the stack with no vent? The stack in my images also has a bathtub drain and toilet tied to it - all of this on the ground floor with no other drains or vents on this stack. I have provided two images - a photo "current" and the other image is a mock-up of my plan. I intend to move the washer drain over (laundry room is behind this wall) and add two bathroom sinks in place of a single sink.

I created a new plan with a vent for the washing machine and a shared vent for the 2 sinks - using 2" pipe for all drains and vents. Do I need the washer vent in this setup? Can I share one vent with 2 sinks? Please refer to my mock-up below and let me know what you think.

Would you mind reviewing the diagram I created in response to your feedback? It is intended to show the flow of the drains and vents but not the fitting details. All pipes are pvc: 3" stack, 2" drains, 1.5" vents, and 1.25" sink drain traps. I would have set up both lavs like the one on the right but there is no room in the wall to cross a drain and a vent.

The revent is at 42" or higher off the floor.
The washer standpipe is at least 18" long.
I typically rough the lavs at 20" from the floor with a 32" counter.
The washer box works well at 48" to the top of the box. It can be lower than that, but the standpipe must be 18" at the min. I buy the washer shutoffs with hammer arrestors.